


File::Path(3p)   Perl Programmers Reference Guide  File::Path(3p)


NAME
       File::Path - Create or remove directory trees

VERSION
       This document describes version 2.04 of File::Path,
       released 2007-11-13.

SYNOPSIS
           use File::Path;

           # modern
           mkpath( 'foo/bar/baz', '/zug/zwang', {verbose => 1} );

           rmtree(
               'foo/bar/baz', '/zug/zwang',
               { verbose => 1, error  => \my $err_list }
           );

           # traditional
           mkpath(['/foo/bar/baz', 'blurfl/quux'], 1, 0711);
           rmtree(['foo/bar/baz', 'blurfl/quux'], 1, 1);

DESCRIPTION
       The "mkpath" function provides a convenient way to create
       directories of arbitrary depth. Similarly, the "rmtree"
       function provides a convenient way to delete an entire
       directory subtree from the filesystem, much like the Unix
       command "rm -r".

       Both functions may be called in one of two ways, the
       traditional, compatible with code written since the dawn
       of time, and modern, that offers a more flexible and
       readable idiom. New code should use the modern interface.

       FUNCTIONS

       The modern way of calling "mkpath" and "rmtree" is with a
       list of directories to create, or remove, respectively,
       followed by an optional hash reference containing keys to
       control the function's behaviour.

       "mkpath"

       The following keys are recognised as parameters to
       "mkpath".  The function returns the list of files actually
       created during the call.

         my @created = mkpath(
           qw(/tmp /flub /home/nobody),
           {verbose => 1, mode => 0750},
         );
         print "created $_\n" for @created;





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       mode
           The numeric permissions mode to apply to each created
           directory (defaults to 0777), to be modified by the
           current "umask". If the directory already exists (and
           thus does not need to be created), the permissions
           will not be modified.

           "mask" is recognised as an alias for this parameter.

       verbose
           If present, will cause "mkpath" to print the name of
           each directory as it is created. By default nothing is
           printed.

       error
           If present, will be interpreted as a reference to a
           list, and will be used to store any errors that are
           encountered.  See the ERROR HANDLING section for more
           information.

           If this parameter is not used, certain error
           conditions may raise a fatal error that will cause the
           program will halt, unless trapped in an "eval" block.

       "rmtree"

       verbose
           If present, will cause "rmtree" to print the name of
           each file as it is unlinked. By default nothing is
           printed.

       safe
           When set to a true value, will cause "rmtree" to skip
           the files for which the process lacks the required
           privileges needed to delete files, such as delete
           privileges on VMS. In other words, the code will make
           no attempt to alter file permissions. Thus, if the
           process is interrupted, no filesystem object will be
           left in a more permissive mode.

       keep_root
           When set to a true value, will cause all files and
           subdirectories to be removed, except the initially
           specified directories. This comes in handy when
           cleaning out an application's scratch directory.

             rmtree( '/tmp', {keep_root => 1} );

       result
           If present, will be interpreted as a reference to a
           list, and will be used to store the list of all files
           and directories unlinked during the call. If nothing
           is unlinked, a reference to an empty list is returned
           (rather than "undef").



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             rmtree( '/tmp', {result => \my $list} );
             print "unlinked $_\n" for @$list;

           This is a useful alternative to the "verbose" key.

       error
           If present, will be interpreted as a reference to a
           list, and will be used to store any errors that are
           encountered.  See the ERROR HANDLING section for more
           information.

           Removing things is a much more dangerous proposition
           than creating things. As such, there are certain
           conditions that "rmtree" may encounter that are so
           dangerous that the only sane action left is to kill
           the program.

           Use "error" to trap all that is reasonable (problems
           with permissions and the like), and let it die if
           things get out of hand. This is the safest course of
           action.

       TRADITIONAL INTERFACE

       The old interfaces of "mkpath" and "rmtree" take a
       reference to a list of directories (to create or remove),
       followed by a series of positional, numeric, modal
       parameters that control their behaviour.

       This design made it difficult to add additional
       functionality, as well as posed the problem of what to do
       when the calling code only needs to set the last
       parameter. Even though the code doesn't care how the
       initial positional parameters are set, the programmer is
       forced to learn what the defaults are, and specify them.

       Worse, if it turns out in the future that it would make
       more sense to change the default behaviour of the first
       parameter (for example, to avoid a security
       vulnerability), all existing code will remain hard-wired
       to the wrong defaults.

       Finally, a series of numeric parameters are much less
       self-documenting in terms of communicating to the reader
       what the code is doing. Named parameters do not have this
       problem.

       In the traditional API, "mkpath" takes three arguments:

       o   The name of the path to create, or a reference to a
           list of paths to create,

       o   a boolean value, which if TRUE will cause "mkpath" to
           print the name of each directory as it is created



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           (defaults to FALSE), and

       o   the numeric mode to use when creating the directories
           (defaults to 0777), to be modified by the current
           umask.

       It returns a list of all directories (including
       intermediates, determined using the Unix '/' separator)
       created.  In scalar context it returns the number of
       directories created.

       If a system error prevents a directory from being created,
       then the "mkpath" function throws a fatal error with
       "Carp::croak". This error can be trapped with an "eval"
       block:

         eval { mkpath($dir) };
         if ($@) {
           print "Couldn't create $dir: $@";
         }

       In the traditional API, "rmtree" takes three arguments:

       o   the root of the subtree to delete, or a reference to a
           list of roots. All of the files and directories below
           each root, as well as the roots themselves, will be
           deleted. If you want to keep the roots themselves, you
           must use the modern API.

       o   a boolean value, which if TRUE will cause "rmtree" to
           print a message each time it examines a file, giving
           the name of the file, and indicating whether it's
           using "rmdir" or "unlink" to remove it, or that it's
           skipping it.  (defaults to FALSE)

       o   a boolean value, which if TRUE will cause "rmtree" to
           skip any files to which you do not have delete access
           (if running under VMS) or write access (if running
           under another OS). This will change in the future when
           a criterion for 'delete permission' under OSs other
           than VMS is settled.  (defaults to FALSE)

       It returns the number of files, directories and symlinks
       successfully deleted.  Symlinks are simply deleted and not
       followed.

       Note also that the occurrence of errors in "rmtree" using
       the traditional interface can be determined only by
       trapping diagnostic messages using $SIG{__WARN__}; it is
       not apparent from the return value. (The modern interface
       may use the "error" parameter to record any problems
       encountered).





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       ERROR HANDLING

       If "mkpath" or "rmtree" encounter an error, a diagnostic
       message will be printed to "STDERR" via "carp" (for non-
       fatal errors), or via "croak" (for fatal errors).

       If this behaviour is not desirable, the "error" attribute
       may be used to hold a reference to a variable, which will
       be used to store the diagnostics. The result is a
       reference to a list of hash references. For each hash
       reference, the key is the name of the file, and the value
       is the error message (usually the contents of $!). An
       example usage looks like:

         rmpath( 'foo/bar', 'bar/rat', {error => \my $err} );
         for my $diag (@$err) {
           my ($file, $message) = each %$diag;
           print "problem unlinking $file: $message\n";
         }

       If no errors are encountered, $err will point to an empty
       list (thus there is no need to test for "undef"). If a
       general error is encountered (for instance, "rmtree"
       attempts to remove a directory tree that does not exist),
       the diagnostic key will be empty, only the value will be
       set:

         rmpath( '/no/such/path', {error => \my $err} );
         for my $diag (@$err) {
           my ($file, $message) = each %$diag;
           if ($file eq '') {
             print "general error: $message\n";
           }
         }

       NOTES

       "File::Path" blindly exports "mkpath" and "rmtree" into
       the current namespace. These days, this is considered bad
       style, but to change it now would break too much code.
       Nonetheless, you are invited to specify what it is you are
       expecting to use:

         use File::Path 'rmtree';

       HEURISTICS

       The functions detect (as far as possible) which way they
       are being called and will act appropriately. It is
       important to remember that the heuristic for detecting the
       old style is either the presence of an array reference, or
       two or three parameters total and second and third
       parameters are numeric. Hence...




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           mkpath 486, 487, 488;

       ... will not assume the modern style and create three
       directories, rather it will create one directory
       verbosely, setting the permission to 0750 (488 being the
       decimal equivalent of octal 750). Here, old style trumps
       new. It must, for backwards compatibility reasons.

       If you want to ensure there is absolutely no ambiguity
       about which way the function will behave, make sure the
       first parameter is a reference to a one-element list, to
       force the old style interpretation:

           mkpath [486], 487, 488;

       and get only one directory created. Or add a reference to
       an empty parameter hash, to force the new style:

           mkpath 486, 487, 488, {};

       ... and hence create the three directories. If the empty
       hash reference seems a little strange to your eyes, or you
       suspect a subsequent programmer might helpfully optimise
       it away, you can add a parameter set to a default value:

           mkpath 486, 487, 488, {verbose => 0};

       SECURITY CONSIDERATIONS

       There were race conditions 1.x implementations of
       File::Path's "rmtree" function (although sometimes patched
       depending on the OS distribution or platform). The 2.0
       version contains code to avoid the problem mentioned in
       CVE-2002-0435.

       See the following pages for more information:

         http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=286905
         http://www.nntp.perl.org/group/perl.perl5.porters/2005/01/msg97623.html
         http://www.debian.org/security/2005/dsa-696

       Additionally, unless the "safe" parameter is set (or the
       third parameter in the traditional interface is TRUE),
       should a "rmtree" be interrupted, files that were
       originally in read-only mode may now have their
       permissions set to a read-write (or "delete OK") mode.

DIAGNOSTICS
       FATAL errors will cause the program to halt ("croak"),
       since the problem is so severe that it would be dangerous
       to continue. (This can always be trapped with "eval", but
       it's not a good idea. Under the circumstances, dying is
       the best thing to do).




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       SEVERE errors may be trapped using the modern interface.
       If the they are not trapped, or the old interface is used,
       such an error will cause the program will halt.

       All other errors may be trapped using the modern
       interface, otherwise they will be "carp"ed about. Program
       execution will not be halted.

       mkdir [path]: [errmsg] (SEVERE)
           "mkpath" was unable to create the path. Probably some
           sort of permissions error at the point of departure,
           or insufficient resources (such as free inodes on
           Unix).

       No root path(s) specified
           "mkpath" was not given any paths to create. This
           message is only emitted if the routine is called with
           the traditional interface.  The modern interface will
           remain silent if given nothing to do.

       No such file or directory
           On Windows, if "mkpath" gives you this warning, it may
           mean that you have exceeded your filesystem's maximum
           path length.

       cannot fetch initial working directory: [errmsg]
           "rmtree" attempted to determine the initial directory
           by calling "Cwd::getcwd", but the call failed for some
           reason. No attempt will be made to delete anything.

       cannot stat initial working directory: [errmsg]
           "rmtree" attempted to stat the initial directory
           (after having successfully obtained its name via
           "getcwd"), however, the call failed for some reason.
           No attempt will be made to delete anything.

       cannot chdir to [dir]: [errmsg]
           "rmtree" attempted to set the working directory in
           order to begin deleting the objects therein, but was
           unsuccessful. This is usually a permissions issue. The
           routine will continue to delete other things, but this
           directory will be left intact.

       directory [dir] changed before chdir, expected dev=[n]
       inode=[n], actual dev=[n] ino=[n], aborting. (FATAL)
           "rmtree" recorded the device and inode of a directory,
           and then moved into it. It then performed a "stat" on
           the current directory and detected that the device and
           inode were no longer the same. As this is at the heart
           of the race condition problem, the program will die at
           this point.

       cannot make directory [dir] read+writeable: [errmsg]
           "rmtree" attempted to change the permissions on the



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           current directory to ensure that subsequent unlinkings
           would not run into problems, but was unable to do so.
           The permissions remain as they were, and the program
           will carry on, doing the best it can.

       cannot read [dir]: [errmsg]
           "rmtree" tried to read the contents of the directory
           in order to acquire the names of the directory entries
           to be unlinked, but was unsuccessful. This is usually
           a permissions issue. The program will continue, but
           the files in this directory will remain after the
           call.

       cannot reset chmod [dir]: [errmsg]
           "rmtree", after having deleted everything in a
           directory, attempted to restore its permissions to the
           original state but failed. The directory may wind up
           being left behind.

       cannot chdir to [parent-dir] from [child-dir]: [errmsg],
       aborting. (FATAL)
           "rmtree", after having deleted everything and restored
           the permissions of a directory, was unable to chdir
           back to the parent. This is usually a sign that
           something evil this way comes.

       cannot stat prior working directory [dir]: [errmsg],
       aborting. (FATAL)
           "rmtree" was unable to stat the parent directory after
           have returned from the child. Since there is no way of
           knowing if we returned to where we think we should be
           (by comparing device and inode) the only way out is to
           "croak".

       previous directory [parent-dir] changed before entering
       [child-dir], expected dev=[n] inode=[n], actual dev=[n]
       ino=[n], aborting. (FATAL)
           When "rmtree" returned from deleting files in a child
           directory, a check revealed that the parent directory
           it returned to wasn't the one it started out from.
           This is considered a sign of malicious activity.

       cannot make directory [dir] writeable: [errmsg]
           Just before removing a directory (after having
           successfully removed everything it contained),
           "rmtree" attempted to set the permissions on the
           directory to ensure it could be removed and failed.
           Program execution continues, but the directory may
           possibly not be deleted.

       cannot remove directory [dir]: [errmsg]
           "rmtree" attempted to remove a directory, but failed.
           This may because some objects that were unable to be
           removed remain in the directory, or a permissions



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           issue. The directory will be left behind.

       cannot restore permissions of [dir] to [0nnn]: [errmsg]
           After having failed to remove a directory, "rmtree"
           was unable to restore its permissions from a
           permissive state back to a possibly more restrictive
           setting. (Permissions given in octal).

       cannot make file [file] writeable: [errmsg]
           "rmtree" attempted to force the permissions of a file
           to ensure it could be deleted, but failed to do so. It
           will, however, still attempt to unlink the file.

       cannot unlink file [file]: [errmsg]
           "rmtree" failed to remove a file. Probably a
           permissions issue.

       cannot restore permissions of [file] to [0nnn]: [errmsg]
           After having failed to remove a file, "rmtree" was
           also unable to restore the permissions on the file to
           a possibly less permissive setting. (Permissions given
           in octal).

SEE ALSO
       o   File::Remove

           Allows files and directories to be moved to the
           Trashcan/Recycle Bin (where they may later be restored
           if necessary) if the operating system supports such
           functionality. This feature may one day be made
           available directly in "File::Path".

       o   File::Find::Rule

           When removing directory trees, if you want to examine
           each file to decide whether to delete it (and possibly
           leaving large swathes alone), File::Find::Rule offers
           a convenient and flexible approach to examining
           directory trees.

BUGS
       Please report all bugs on the RT queue:

       <http://rt.cpan.org/NoAuth/Bugs.html?Dist=File-Path>

ACKNOWLEDGEMENTS
       Paul Szabo identified the race condition originally, and
       Brendan O'Dea wrote an implementation for Debian that
       addressed the problem.  That code was used as a basis for
       the current code. Their efforts are greatly appreciated.

AUTHORS
       Tim Bunce <Tim.Bunce@ig.co.uk> and Charles Bailey
       <bailey@newman.upenn.edu>. Currently maintained by David



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       Landgren <david@landgren.net>.

COPYRIGHT
       This module is copyright (C) Charles Bailey, Tim Bunce and
       David Landgren 1995-2007.  All rights reserved.

LICENSE
       This library is free software; you can redistribute it
       and/or modify it under the same terms as Perl itself.
















































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